Bacteriophage Host Range Engineering

Technology

Researchers at MIT have developed a new method for addressing the challenges faced in engineering bacteriophage host ranges.  First, mutations are inserted into the tail region of phage DNA with PCR while the rest of the phage genome is amplified without mutagenesis.  These DNA fragments are then assembled into a fully functional synthetic phage genome by transformation into yeast and amplified in yeast thanks to recombination with yeast artificial chromosome (YAC).  The resulting phage genome is extracted from the yeast, and then transfected into a bacterium where it resumes its life cycle and produces progeny with the desired mutations. This phage population can then be tested for host range specificity.  Using this method allows for systematically generating and selecting phage variants with desired functionality.  

Problem Addressed

Overcoming the development of antibiotic resistance in pathogenic bacteria poses a tremendous medical challenge. Whereas small molecule drugs have been the standard antibiotic for several decades, bacteriophages, or viruses that infect bacteria, could prove to be a viable alternative.  One significant challenge of bacteriophage-based therapy, is the specificity of each virus; thus, simultaneously targeting multiple bacteria in an infection would require a cocktail of viruses, complicating both development of therapies and increasing the associated regulatory hurdles.  One solution would be to engineer a single bacteriophage to target multiple hosts; however, current techniques for bacteriophage engineering are low in efficiency and throughput.  

Advantages

• Systematically modify bacteriophage genome for wider range of specificities
• Allows for modifying bacteriophage in non-bacterial host
• Efficient and versatile method   

Publications

"Engineering Modular Viral Scaffolds for Targeted Bacterial Population Editing." Cell Systems 1, no. 3 (2015): 187–196.